Kotaro Kannagi is a high school student who first appears in the series Code-E and continues to play a role in Mission-E. He is a classmate of the protagonist Chinami Ebihara and serves as the head and sole member of the school's Science Research Club, where he can frequently be found absorbed in his work. His most prominent trait is being an absent-minded genius, characterized by a profound intellectual curiosity that often makes him oblivious to the social and emotional subtleties around him. Initially, his motivations are entirely scientific. Upon witnessing Chinami Ebihara's ability to emit electromagnetic waves, he becomes intensely focused on studying and understanding this phenomenon, asking if he can date her purely in the name of research. This singular focus defines his early role, creating narrative tension through his obliviousness to the feelings of others, particularly his childhood friend Sonomi Kujo, who is in love with him. His role in Code-E is central, as his actions bring Chinami's powers into the open and create the core relationship dynamics. In Mission-E, his position shifts to that of a supporting character, using his scientific expertise to assist Chinami and the organization OZ as they navigate conflicts involving other Type-E users. The key relationship of his life is with Chinami, which grows from a detached scientific inquiry into a genuine, heartfelt bond. Likewise, his bond with Sonomi is complex, defined by her unrequited love for him and the jealousy she feels towards Chinami, though she ultimately plays an instrumental role in helping him understand his own emotions. Over the course of the story, Kotaro experiences marked development. He gradually moves beyond his narrow scientific worldview, eventually realizing and confessing his love for Chinami. This emotional awakening allows him to balance his intellectual pursuits with meaningful personal relationships. Kotaro does not possess any supernatural abilities himself; his primary defining capability is his high intellect and talent for invention and problem-solving, which makes him a valuable scientific asset to the group.